Can't seem to find <navmeshmodifier> component in script

I’m trying to upgrade to the new AI navigation package and whilst I was able to add the “NavMeshModifier” component to my objects in the editor and change the values there.
I can’t seem to get the component by script… I’m using UnityEngine.AI and can see navmeshagent component for example… but I can’t see / get the “NavMeshModifier” component — any ideas on what I’m missing / doing wrong?

Self-Answer… I found I was missing:
using Unity.AI.Navigation;

using UnityEngine is not sufficient